Permitted development rights on a converted dwelling

Permitted development rights after a Class MA conversion are much narrower than most buyers assume, and for flats they are largely absent. Part 1 of Schedule 2 to the GPDO 2015, which contains the householder rights people think of as permitted development, applies to a dwellinghouse, and a dwellinghouse for those purposes does not include a building containing one or more flats or a flat within such a building.

So a converted office producing six flats gives those flats no Part 1 rights at all. A converted building producing a single house does carry Part 1 rights, with conditions, and with a couple of traps that catch even experienced agents.

Rights attaching to a new dwelling

A dwelling created through prior approval under Part 3 is a dwelling like any other for use class purposes. Its permitted development position depends on its form rather than on how it came about.

Where the conversion produces a single dwellinghouse, Part 1 rights are available in principle: extensions under Class A, roof alterations under Class B, outbuildings under Class E, porches, hard surfaces, and the rest. Where it produces flats, Part 1 is unavailable.

Part 14 rights for solar and other microgeneration, and Part 2 rights for gates, fences and walls and for exterior painting, are drafted differently from Part 1 and need checking class by class rather than assumed. The limits on solar in particular catch people out, as set out in domestic solar panels and the 200 mm projection limit.

Why flats have limited rights

The exclusion is definitional rather than discretionary. The Order's meaning of dwellinghouse for Part 1 purposes carves out flats and buildings containing flats, so there is nothing to argue about.

Practically, this means a leaseholder in a converted building cannot add a rear extension, a dormer, a rooflight in some circumstances, an outbuilding or a hard standing under permitted development. Every one of those needs a planning application, and in a converted commercial building it will also need freeholder consent and probably a lease variation.

It also means the building as a whole cannot be extended under Part 1 by anyone. The freeholder has no householder rights over a block of flats.

Tell purchasers this before exchange rather than after. A buyer who expects to add a conservatory to a ground floor flat has been mis-sold the property by their own assumption.

Conditions imposed by the prior approval

Prior approval decisions carry conditions of two kinds and both bind the finished dwelling.

First, conditions built into the class itself in Schedule 2. Several Part 3 classes require the development to be completed within three years of the date of prior approval, and that condition runs with the development rather than lapsing on completion of the sale.

Second, conditions the authority attaches when granting prior approval, dealing with the matters it was entitled to consider. Contamination remediation and verification, noise mitigation and glazing specification, flood resilience measures, parking and cycle storage layout, refuse storage, and natural light provision. Those conditions remain enforceable against the building afterwards.

Read the decision notice rather than the summary on the council's website. A condition requiring acoustic glazing to be retained in perpetuity is easy to breach by replacing windows, and it converts a routine refurbishment into a breach of planning control.

Further conversion or subdivision

Subdividing a house into two or more flats is a material change of use and requires planning permission. There is no permitted development route for it, and this is where owners of Class Q and Class MA conversions most often go wrong.

Subdividing an existing flat is likewise a material change of use. Merging two flats into one is too, though it is rarely enforced against.

Changing a single dwellinghouse to a small house in multiple occupation for up to six residents is permitted development under Part 3 unless an Article 4 direction has been made, and many authorities in university and coastal towns have made such directions. Check the council's published list of directions in force rather than assuming.

Extensions to a converted building

Where the conversion produced a single dwellinghouse and Part 1 rights are available, two limits do most of the damage.

Class A limits the proportion of the curtilage that may be covered by buildings, and on a conversion the curtilage may be small or tightly defined. Class Q in particular restricts the land that comes with the conversion to an area related to the building's footprint, so the curtilage available for outbuildings and extensions can be almost nothing. That point is explored further in the Class Q structural works test.

Class AA, the upward extension right for a dwellinghouse, requires the house to have been built between 1 July 1948 and 28 October 2018. A dwelling created by converting an older agricultural or commercial building is not a house built within that window, so the right does not apply.

Article 2(3) land, meaning conservation areas, National Parks, National Landscapes, World Heritage Sites and the Broads, removes or narrows several Part 1 rights in any event. Many rural conversions sit on it.

Checking the approval before buying

Work through the same list every time:

1. Obtain the prior approval decision notice in full, with the approved plans, not just the online summary.
2. Check every condition, including completion timing, and whether each has been complied with.
3. Check whether any condition removes or restricts permitted development rights expressly.
4. Establish whether the finished building contains flats or a single dwellinghouse, since that decides Part 1 entirely.
5. Check for an Article 4 direction covering the site, and whether it affects householder rights or houses in multiple occupation.
6. Check whether the site is on article 2(3) land.
7. Where any works have already been carried out, consider whether a certificate of lawfulness is appropriate, since that is the only formal way to confirm that works are lawful.

Point three is worth a specific enquiry. Prior approval conditions occasionally restrict subsequent alterations, and a condition of that kind is easy to miss in a bundle.

Advising a purchaser correctly

Put the position in writing and keep it short. What the building is in planning terms, which rights are available, which are excluded and why, and what will need an application.

The most useful sentence you can give a residential purchaser is that a flat has no householder permitted development rights whatever. The second most useful is that a conversion completed under prior approval carries live conditions which a later owner inherits.

Where the property is being marketed on its potential, and that potential depends on rights the building does not have, say so before the offer rather than after. A planning statement prepared for any subsequent application should set out the prior approval history and the conditions in force, because the case officer will find them anyway.

For the planning position on exterior finishes, which sits in a different part of the Order again, see painting a house exterior and the permitted development limits. The report index shows what a full application on a converted building is likely to need.

PlanScope provides AI-assisted draft reports for planning applications. Reports should be reviewed before submission. We do not guarantee planning approval.

This is general guidance, not legal advice; check the position with your local planning authority or a qualified professional before relying on it. A lawful development certificate is the only formal way to confirm that works are lawful.